Method and System for Synchronizing a Clock for an Adjacent Network to a Clock for an Overlay Network

1. A method of synchronizing a clock for an adjacent network (AN) to a clock for an overlay network (ON), comprising: determining whether a wireless access point for the AN is providing service to at least one mobile station in a service area of the wireless access point; in response to determining that the wireless access point is not providing service to at least one mobile station: determining that the AN is in an idle mode and able to receive an ON clock signal from the ON; extracting the ON clock signal from an outgoing signal transmitted wirelessly from the ON; synchronizing the AN clock to the ON clock based on the extracted ON clock signal; extracting a system time from the outgoing signal; determining whether location information of the ON is available; and resynchronizing the AN clock to the ON clock based on at least the extracted system time and the location information in response to determining that the location information of the ON is available.

2. The method as set forth in claim 1 , the outgoing signal comprising a signal in an overhead channel transmitted from the ON.

3. The method as set forth in claim 2 , further comprising monitoring the overhead channel.

4. The method as set forth in claim 1 , further comprising: establishing a reference time for the AN based on the extracted system time.

5. The method as set forth in claim 1 , wherein resynchronizing the AN clock comprises: extracting location information for the overlay network; determining a one-way delay between the ON and the AN based on the location information and the reference time; and resynchronizing the AN clock to the ON clock based on the one-way delay.

6. The method as set forth in claim 1 , wherein the AN is an underlay network providing service within a portion of a service area of the overlay network.

7. The method as set forth in claim 1 , further comprising: in response to determining that the wireless access point is providing service to at least one mobile station: determining that the AN is in a traffic mode and unable to monitor an overhead channel of ON; requesting at least one timing report from at least one mobile station; receiving the at least one timing report from the at least one mobile station; and resynchronizing the AN clock to the ON clock based on the at least one timing report.

8. The method as set forth in claim 7 , the timing report comprising an ON time offset reference.

9. The method as set forth in claim 1 , further comprising clocking the AN using the synchronized AN clock signal.

10. A method of synchronizing a clock for an adjacent network (AN) to a clock for an overlay network (ON), comprising: determining whether a wireless access point for the AN is providing service to at least one mobile station in a service area of the wireless access point; in response to determining that the wireless access point is not providing service to at least one mobile station: determining that the AN is in an idle mode; synchronizing the AN clock to the ON clock based on an ON clock signal extracted from an outgoing signal transmitted wirelessly from the ON; and resynchronizing the AN clock to the ON clock based on at least an extracted time and location information when the location information of the ON is available; and in response to determining that the wireless access point is providing service to at least one mobile station: determining that the AN is in a traffic mode; requesting a plurality of timing reports at a specified frequency from the at least one mobile station; receiving the timing reports from the at least one mobile station at the specified frequency; and for each timing report received from the at least one mobile station, determining whether to resynchronize the AN clock to the ON clock based on the received timing report.

11. The method as set forth in claim 10 , each timing report comprising an ON time offset reference.

12. The method as set forth in claim 11 , determining whether to resynchronize the AN clock to the ON clock based on the received timing report comprising: comparing the received ON time offset reference to a known ON time offset reference; and determining whether to resynchronize the AN clock to the ON clock based on the comparison of the received ON time offset reference, the ON time offset reference associated with an offset between a system time of the ON and a reference time of the AN.

13. The method as set forth in claim 12 , further comprising, when the AN is in the idle mode: monitoring an overhead channel transmitted by the ON; extracting the system time of the ON from the overhead channel; and establishing the reference time of the AN based on the extracted system time.

14. An apparatus configured to synchronize a clock for an adjacent network (AN) to a clock for an overlay network (ON), the apparatus comprising: a clock synchronizer configured to determine whether a wireless access point for the AN is providing service to at least one mobile station in a service area of the wireless access point, and in response to determining that the wireless access point is not providing service to at least one mobile station, determine that the AN is in an idle mode and able to receive an ON clock signal from the ON, extract the ON clock signal from an outgoing signal transmitted wirelessly from the ON, and synchronize the AN clock to the ON clock based on the extracted ON clock signal; a system time extractor configured to extract a system time from the outgoing signal when the AN is in the idle mode; and a clock resynchronizer configured to resynchronize the AN clock to the ON clock based on at least the extracted system time and location information of the ON when the AN is in the idle mode and the location information of the ON is available.

15. The apparatus as set forth in claim 14 , the AN clock configured to clock the AN by generating the synchronized AN clock signal.

16. The apparatus as set forth in claim 14 , the clock synchronizer further configured to monitor an overhead channel for the outgoing signal when the AN is in the idle mode, wherein the ON clock signal is transmitted on the overhead channel.

17. The apparatus as set forth in claim 14 , wherein the system time extractor is further configured to, when the AN is in the idle mode, monitor an overhead channel and establish a reference time for the AN based on the extracted system time.

18. The apparatus as set forth in claim 17 , wherein the clock resynchronizer is further configured to, when the AN is in the idle mode and the location information for the ON is available, extract the location information for the ON, determine a one-way delay between the ON and the AN based on the location information and the reference time, and resynchronize the AN clock to the ON clock based on the one-way delay.

19. The apparatus as set forth in claim 18 , wherein the clock resynchronizer is further configured to, in response to determining that the wireless access point is providing service to at least one mobile station, determine that the AN is in a traffic mode and unable to monitor an overhead channel of ON, receive at least one timing report from at least one mobile station, and resynchronize the AN clock to the ON clock based on the at least one timing report.

20. The apparatus as set forth in claim 14 , wherein the AN is an underlay network providing service within a portion of a service area of the overlay network.